[alsa-devel] [PATCH 1/2] ALSA: hda - Avoid unnecessary parameter read for EPSS

[Takashi Iwai]

EPSS parameter should be static, so we can read it once and remember.
This also allows more easily to override the wrong EPSS capability
reported from a codec by changing the flag in the codec
initialization step.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/hda/hda_codec.c | 10 ++++++++--
 sound/pci/hda/hda_codec.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index f560051..f25c24c 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1209,6 +1209,9 @@ static void snd_hda_codec_free(struct hda_codec *codec)
 	kfree(codec);
 }
 
+static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec,
+				hda_nid_t fg, unsigned int power_state);
+
 static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
 				unsigned int power_state);
 
@@ -1317,6 +1320,10 @@ int /*__devinit*/ snd_hda_codec_new(struct hda_bus *bus,
 					   AC_VERB_GET_SUBSYSTEM_ID, 0);
 	}
 
+	codec->epss = snd_hda_codec_get_supported_ps(codec,
+					codec->afg ? codec->afg : codec->mfg,
+					AC_PWRST_EPSS);
+
 	/* power-up all before initialization */
 	hda_set_power_state(codec,
 			    codec->afg ? codec->afg : codec->mfg,
@@ -3543,8 +3550,7 @@ static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
 	/* this delay seems necessary to avoid click noise at power-down */
 	if (power_state == AC_PWRST_D3) {
 		/* transition time less than 10ms for power down */
-		bool epss = snd_hda_codec_get_supported_ps(codec, fg, AC_PWRST_EPSS);
-		msleep(epss ? 10 : 100);
+		msleep(codec->epss ? 10 : 100);
 	}
 
 	/* repeat power states setting at most 10 times*/
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 7fbc1bc..e5a7e19 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -862,6 +862,7 @@ struct hda_codec {
 	unsigned int ignore_misc_bit:1; /* ignore MISC_NO_PRESENCE bit */
 	unsigned int no_jack_detect:1;	/* Machine has no jack-detection */
 	unsigned int pcm_format_first:1; /* PCM format must be set first */
+	unsigned int epss:1;		/* supporting EPSS? */
 #ifdef CONFIG_SND_HDA_POWER_SAVE
 	unsigned int power_on :1;	/* current (global) power-state */
 	int power_transition;	/* power-state in transition */
-- 
1.7.11.4